Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Electric vehicle
Reexamination Certificate
1999-10-19
2001-11-13
Camby, Richard M. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Electric vehicle
C701S067000, C701S068000, C180S065230
Reexamination Certificate
active
06317665
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to a control system for a vehicle in which a fuel combustion-driven engine and a motor/generator are provided as interchangeable drive sources, and in which a transmission with a lock-up clutch is provided which is directly couplable between the drive sources and a drive wheel.
2. Description of Related Art
In a vehicle that has an engine, fuel is combusted within the engine, generating heat energy, and this heat energy is converted to mechanical energy (drive force) to drive the vehicle. With an engine, the driving region at which combustion efficiency is good and high torque can be obtained is limited to a relatively narrow r.p.m. range. Therefore, in a vehicle that uses an engine as the drive source, the engine r.p.m. and engine torque are changed by a transmission depending on a driving condition, and transmitted to the vehicle wheel(s).
Incidentally, in recent years, so-called hybrid vehicles have been proposed that have a different type of drive source, with objects of conserving the fuel which drives the engine, reducing the noise due to engine revolution, and reducing the exhaust gas that is generated through combustion of the fuel.
In these hybrid vehicles, too, a transmission is provided between the drive source and the drive wheel(s), but it is widely proposed to use a transmission with a torque converter, the same as is used in normal vehicles.
Additionally, there are many proposals to use a torque converter that is equipped with a directly couplable lock-up clutch, because the transmission efficiency in a conventional torque converter declines because fluid transmission is performed. For example, a hybrid vehicle disclosed in Japanese Laid-Open application 8-168104 also has a torque converter with a lock-up clutch as described above.
SUMMARY OF THE INVENTION
Incidentally, hybrid vehicles were developed with primary objects of reducing fuel consumption and reducing exhaust emissions, and require the driving be done as much as possible with the lock-up clutch engaged. However, if the drive source is switched while the lock-up clutch is engaged, the torque change that occurs at starting and/or stopping of the engine is transmitted to the gear mechanism of an automatic transmission as a shock, and this shock is transmitted to the vehicle body.
Therefore, it is attempted to prevent, as much as possible, the transmission of the shock of switching the drive source while the lock-up clutch is engaged. However, in the above-described vehicle, when the lock-up clutch is engaged and the vehicle is, driven by the drive force of the engine, a rotary force is applied by a motor/generator to negate the vibration of the engine in order to control the vibration of the engine that is generated, especially during deceleration. This does not solve the above-mentioned problems.
This invention was made in the above-described background, and has an object of preventing transmission of the shock of switching drive sources in a vehicle having a fuel combustion-driven engine and a motor/generator drive source provided as interchangeable drive sources, and in which a transmission with a lock-up clutch is provided which is directly couplable between the drive sources and a drive wheel.
A first aspect of the invention provides a control system for a vehicle in which a fuel combustion-driven engine and a motor/generator are provided as interchangeable drive sources, and in which a transmission with a lock-up clutch is provided which is directly couplable between the drive sources and a drive wheel, wherein, when the drive source is switched between the engine and the motor/generator, the engaged lock-up clutch is temporarily placed in a disengaged state or a half-engaged state.
With a control system thus structured, when the vehicle drive source is switched between the engine and the motor/generator, the engaged lock-up clutch is temporarily placed in a disengaged state or a half-engaged state.
A second aspect of the invention provides a control system for a vehicle in which a fuel combustion-driven engine and a motor/generator are provided as interchangeable drive sources, and in which a transmission with a lock-up clutch is provided which is directly couplable between the drive sources and a drive wheel, wherein, when the drive source is switched from the motor/generator to the engine while the vehicle is stopped, switching is performed after disengaging the lock-up clutch.
In a control system thus configured, when the drive source is switched from the motor/generator to the engine while the vehicle is stopped, switching is performed after the lock-up clutch is disengaged.
A third aspect of the invention provides a control system for a vehicle in which a fuel combustion-driven engine and a motor/generator are provided as interchangeable drive sources, and in which a transmission with a lock-up clutch is provided which is directly couplable between the drive sources and a drive wheel, wherein, when the drive source is switched from the engine to the motor/generator while the vehicle is stopped, switching is performed after the lock-up clutch is disengaged.
With a control system thus configured, when the drive source is switched from the engine to the motor/generator while the vehicle is stopped, switching is performed after the lock-up clutch is disengaged.
REFERENCES:
patent: 5562565 (1996-10-01), Moroto et al.
patent: 5944630 (1999-08-01), Omote
patent: 6070680 (2000-06-01), Ogama
patent: 6183389 (2001-02-01), Tabata
patent: 8-168104 (1996-06-01), None
Ibaraki Ryuji
Tabata Atsushi
Taga Yutaka
Camby Richard M.
Oliff & Berridg,e PLC
Toyota Jidosha & Kabushiki Kaisha
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